An improved perfusion solution will be tested in vivo in animals for its ability to permit an extension of kidney storage at 0 degrees C. Lower temperatures of unfrozen storage will also be explored, using glycerol in the perfusion solution to lower the freezing temperature. An apparent sensitivity of cell membranes to flexion while under osmotic stress will be investigated to determine the conditions under which the injury occurs and means of preventing it. These techniques will then be used to redesign protocols for kidney freezing.